Temperature Dependence of Paramagnetic Relaxation of Mo5+ in TiO2

The relaxation rate of Mo⁵⁺ in TiO₂ was measured by the measurement of linewidth at temperatures between 77°K and 240°K, and by the saturation and recovery method at temperatures at and below 4.2°K. The linewidth is about 300 G at 240°K, and 0.5 G at 77°K. The relaxation time is about 5 sec at 4.2°K and about 100 min at 1.05°K. The temperature dependence of the relaxation rate is $T^9$ between 3° and 200°K, $T^5$ between 1.5° and 3°K, and T below 1.5°K. At the linear dependence region, i.e., ∼1°K, the magnetic field dependence is $H^4$ as verified by experiments.